Accelerated carbonation of concrete to sequester CO2

This month Arthur Harrisson looks at the phenomenon of accelerated carbonation, its effects in concrete and carbonation methods.

In a recent issue of ‘Concrete’, Davies and Ho¹ discussed the possibilities for carbon storage in concrete through accelerated carbonation. The methods proposed were the use of a chamber to force CO₂ into precast concrete or to include a CO₂-bearing mineral in the cement to cause carbonation in situ and quickly.

Carbonation of cement paste occurs universally where the surface of concrete is in direct contact with the atmosphere, but the movement into the body of the concrete is intentionally limited for reasons of concrete durability. The action of CO₂ on concrete relates to the nature of the products of cement hydration.